Gateway's AsyncPush can not work

[AndyRao]

Hi
I'm trying to use gateway's AsyncPush and I replaced gateway.Push() in sample_client.cc with async one like this.

   std::future<int> returnCodeFuture = gateway.AsyncPush();
    std::future_status status = returnCodeFuture.wait_for(std::chrono::seconds(10));
    if (status == std::future_status::timeout) {
      std::cout << "push gateway timeout  ";
    } else if (status == std::future_status::ready) {
      int returnCode = returnCodeFuture.get();
      if (returnCode != 200) {
        std::cout << "push counter to pushgateway failed " << "return code is: " << returnCode;
      }
      std::cout << "returnCode is " << returnCode << std::endl;

    }

But when I executed this code, I got a segment fault. I don't know why. Is there any examples about asyn push that can work?

[gjasny]

I can reproduce it and will take a look.

[gjasny]

@AndyRao please test #273

[AndyRao]

@gjasny test pass